As countries continue to deal with the pandemic, researchers around the world race to find a vaccine for the coronavirus. The World Health Organization (WHO) lists 170 possible vaccines. These teams of scientists filter the effectiveness of their vaccines through a process of three phases before they can be approved. Vaccines resemble the protein of the virus that they protect against, which allows the immune system to form antibodies. Although vaccines are typically developed after years of testing and large-scale production, researchers strive to finalize a coronavirus vaccine within twelve to eighteen months. The WHO estimates that vaccines will be ready in mid-2021.

As of September 14th, phase 3 has nine candidates, while phase 1 has twenty-nine and phase 2 has eighteen. The remaining 142 vaccines are currently pre-clinical and have not yet been tested in human trials. The preclinical stage tests the vaccines on animals to observe if they become immune to the virus. Then, phase 1 tests them in small-scale human trials as scientists monitor the subjects for effects. When they move onto phase 2, vaccines are placed in expanded versions of the previous trials to determine the proper dosages. The last phase, phase 3, requires the vaccines to pass large-scale efficacy trials to discover any strange side effects. Once vaccines pass the three phases, they can be manufactured and distributed to the public.

Of the nine vaccines that are in phase 3, three of them are from the United States (Johnson & Johnson, Moderna Therapeutics in collaboration with the National Institutes of Health, and Pfizer in collaboration with the German BioNTech). Moderna Therapeutics announced that they should be able to deliver 500 million doses by the beginning of 2021, but skeptics think that it is unlikely that the vaccine will be widely available that early. Pfizer aims to supply 1.3 billion doses by the end of next year.

Other international teams include the partnership of the United Kingdom’s University of Oxford and AstraZeneca, who paused trials in the beginning of September due to an unfavorable result in one participant from the U.K. They later resumed trials in the U.K., Brazil, South Africa, and India, but their U.S. tests are still on hold. Sinovac, a team of a Chinese biopharmaceutical company and Brazil’s research center Butantan will conduct phase 3 in Indonesia and Bangladesh.

Even once a vaccine is approved, it will require time for mass production and distribution. When that happens, the world can finally return to normal.